2 * Copyright (c) 1995, Mike Mitchell
3 * Copyright (c) 1984, 1985, 1986, 1987, 1993
4 * The Regents of the University of California. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by the University of
17 * California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * $FreeBSD: src/sys/netipx/spx_usrreq.c,v 1.27.2.1 2001/02/22 09:44:18 bp Exp $
37 * $DragonFly: src/sys/netproto/ipx/spx_usrreq.c,v 1.20 2007/04/22 01:13:15 dillon Exp $
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/malloc.h>
46 #include <sys/protosw.h>
47 #include <sys/socket.h>
48 #include <sys/socketvar.h>
49 #include <sys/thread2.h>
51 #include <net/route.h>
52 #include <netinet/tcp_fsm.h>
58 #include "spx_timer.h"
60 #include "spx_debug.h"
63 * SPX protocol implementation.
65 static u_short spx_iss;
66 static u_short spx_newchecks[50];
67 static int spx_hardnosed;
68 static int spx_use_delack = 0;
69 static int traceallspxs = 0;
70 static struct spx spx_savesi;
71 static struct spx_istat spx_istat;
73 /* Following was struct spxstat spxstat; */
75 #define spxstat spx_istat.newstats
78 static int spx_backoff[SPX_MAXRXTSHIFT+1] =
79 { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
81 static struct spxpcb *spx_close(struct spxpcb *cb);
82 static struct spxpcb *spx_disconnect(struct spxpcb *cb);
83 static struct spxpcb *spx_drop(struct spxpcb *cb, int errno);
84 static int spx_output(struct spxpcb *cb, struct mbuf *m0);
85 static int spx_reass(struct spxpcb *cb, struct spx *si, struct mbuf *si_m);
86 static void spx_setpersist(struct spxpcb *cb);
87 static void spx_template(struct spxpcb *cb);
88 static struct spxpcb *spx_timers(struct spxpcb *cb, int timer);
89 static struct spxpcb *spx_usrclosed(struct spxpcb *cb);
91 static int spx_usr_abort(struct socket *so);
92 static int spx_accept(struct socket *so, struct sockaddr **nam);
93 static int spx_attach(struct socket *so, int proto,
94 struct pru_attach_info *ai);
95 static int spx_bind(struct socket *so, struct sockaddr *nam,
97 static int spx_connect(struct socket *so, struct sockaddr *nam,
99 static int spx_detach(struct socket *so);
100 static int spx_usr_disconnect(struct socket *so);
101 static int spx_listen(struct socket *so, struct thread *td);
102 static int spx_rcvd(struct socket *so, int flags);
103 static int spx_rcvoob(struct socket *so, struct mbuf *m, int flags);
104 static int spx_send(struct socket *so, int flags, struct mbuf *m,
105 struct sockaddr *addr, struct mbuf *control,
107 static int spx_shutdown(struct socket *so);
108 static int spx_sp_attach(struct socket *so, int proto,
109 struct pru_attach_info *ai);
111 struct pr_usrreqs spx_usrreqs = {
112 .pru_abort = spx_usr_abort,
113 .pru_accept = spx_accept,
114 .pru_attach = spx_attach,
115 .pru_bind = spx_bind,
116 .pru_connect = spx_connect,
117 .pru_connect2 = pru_connect2_notsupp,
118 .pru_control = ipx_control,
119 .pru_detach = spx_detach,
120 .pru_disconnect = spx_usr_disconnect,
121 .pru_listen = spx_listen,
122 .pru_peeraddr = ipx_peeraddr,
123 .pru_rcvd = spx_rcvd,
124 .pru_rcvoob = spx_rcvoob,
125 .pru_send = spx_send,
126 .pru_sense = pru_sense_null,
127 .pru_shutdown = spx_shutdown,
128 .pru_sockaddr = ipx_sockaddr,
129 .pru_sosend = sosend,
130 .pru_soreceive = soreceive,
134 struct pr_usrreqs spx_usrreq_sps = {
135 .pru_abort = spx_usr_abort,
136 .pru_accept = spx_accept,
137 .pru_attach = spx_sp_attach,
138 .pru_bind = spx_bind,
139 .pru_connect = spx_connect,
140 .pru_connect2 = pru_connect2_notsupp,
141 .pru_control = ipx_control,
142 .pru_detach = spx_detach,
143 .pru_disconnect = spx_usr_disconnect,
144 .pru_listen = spx_listen,
145 .pru_peeraddr = ipx_peeraddr,
146 .pru_rcvd = spx_rcvd,
147 .pru_rcvoob = spx_rcvoob,
148 .pru_send = spx_send,
149 .pru_sense = pru_sense_null,
150 .pru_shutdown = spx_shutdown,
151 .pru_sockaddr = ipx_sockaddr,
152 .pru_sosend = sosend,
153 .pru_soreceive = soreceive,
157 static MALLOC_DEFINE(M_SPX_Q, "ipx_spx_q", "IPX Packet Management");
163 spx_iss = 1; /* WRONG !! should fish it out of TODR */
167 spx_input(struct mbuf *m, struct ipxpcb *ipxp)
175 spxstat.spxs_rcvtotal++;
177 panic("No ipxpcb in spx_input\n");
181 cb = ipxtospxpcb(ipxp);
185 if (m->m_len < sizeof(struct spx)) {
186 if ((m = m_pullup(m, sizeof(*si))) == NULL) {
187 spxstat.spxs_rcvshort++;
191 si = mtod(m, struct spx *);
192 si->si_seq = ntohs(si->si_seq);
193 si->si_ack = ntohs(si->si_ack);
194 si->si_alo = ntohs(si->si_alo);
196 so = ipxp->ipxp_socket;
198 if (so->so_options & SO_DEBUG || traceallspxs) {
199 ostate = cb->s_state;
202 if (so->so_options & SO_ACCEPTCONN) {
203 struct spxpcb *ocb = cb;
205 so = sonewconn(so, 0);
210 * This is ugly, but ....
212 * Mark socket as temporary until we're
213 * committed to keeping it. The code at
214 * ``drop'' and ``dropwithreset'' check the
215 * flag dropsocket to see if the temporary
216 * socket created here should be discarded.
217 * We mark the socket as discardable until
218 * we're committed to it below in TCPS_LISTEN.
221 ipxp = (struct ipxpcb *)so->so_pcb;
222 ipxp->ipxp_laddr = si->si_dna;
223 cb = ipxtospxpcb(ipxp);
224 cb->s_mtu = ocb->s_mtu; /* preserve sockopts */
225 cb->s_flags = ocb->s_flags; /* preserve sockopts */
226 cb->s_flags2 = ocb->s_flags2; /* preserve sockopts */
227 cb->s_state = TCPS_LISTEN;
231 * Packet received on connection.
232 * reset idle time and keep-alive timer;
235 cb->s_timer[SPXT_KEEP] = SPXTV_KEEP;
237 switch (cb->s_state) {
240 struct sockaddr_ipx *sipx, ssipx;
241 struct ipx_addr laddr;
244 * If somebody here was carying on a conversation
245 * and went away, and his pen pal thinks he can
246 * still talk, we get the misdirected packet.
248 if (spx_hardnosed && (si->si_did != 0 || si->si_seq != 0)) {
253 bzero(sipx, sizeof *sipx);
254 sipx->sipx_len = sizeof(*sipx);
255 sipx->sipx_family = AF_IPX;
256 sipx->sipx_addr = si->si_sna;
257 laddr = ipxp->ipxp_laddr;
258 if (ipx_nullhost(laddr))
259 ipxp->ipxp_laddr = si->si_dna;
260 if (ipx_pcbconnect(ipxp, (struct sockaddr *)sipx, &thread0)) {
261 ipxp->ipxp_laddr = laddr;
266 dropsocket = 0; /* committed to socket */
267 cb->s_did = si->si_sid;
268 cb->s_rack = si->si_ack;
269 cb->s_ralo = si->si_alo;
270 #define THREEWAYSHAKE
272 cb->s_state = TCPS_SYN_RECEIVED;
273 cb->s_force = 1 + SPXT_KEEP;
274 spxstat.spxs_accepts++;
275 cb->s_timer[SPXT_KEEP] = SPXTV_KEEP;
279 * This state means that we have heard a response
280 * to our acceptance of their connection
281 * It is probably logically unnecessary in this
284 case TCPS_SYN_RECEIVED: {
285 if (si->si_did != cb->s_sid) {
290 ipxp->ipxp_fport = si->si_sport;
291 cb->s_timer[SPXT_REXMT] = 0;
292 cb->s_timer[SPXT_KEEP] = SPXTV_KEEP;
294 cb->s_state = TCPS_ESTABLISHED;
295 spxstat.spxs_accepts++;
300 * This state means that we have gotten a response
301 * to our attempt to establish a connection.
302 * We fill in the data from the other side,
303 * telling us which port to respond to, instead of the well-
304 * known one we might have sent to in the first place.
305 * We also require that this is a response to our
309 if (si->si_did != cb->s_sid) {
313 spxstat.spxs_connects++;
314 cb->s_did = si->si_sid;
315 cb->s_rack = si->si_ack;
316 cb->s_ralo = si->si_alo;
317 cb->s_dport = ipxp->ipxp_fport = si->si_sport;
318 cb->s_timer[SPXT_REXMT] = 0;
319 cb->s_flags |= SF_ACKNOW;
321 cb->s_state = TCPS_ESTABLISHED;
322 /* Use roundtrip time of connection request for initial rtt */
324 cb->s_srtt = cb->s_rtt << 3;
325 cb->s_rttvar = cb->s_rtt << 1;
326 SPXT_RANGESET(cb->s_rxtcur,
327 ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1,
328 SPXTV_MIN, SPXTV_REXMTMAX);
332 if (so->so_options & SO_DEBUG || traceallspxs)
333 spx_trace(SA_INPUT, (u_char)ostate, cb, &spx_savesi, 0);
335 m->m_len -= sizeof(struct ipx);
336 m->m_pkthdr.len -= sizeof(struct ipx);
337 m->m_data += sizeof(struct ipx);
339 if (spx_reass(cb, si, m)) {
342 if (cb->s_force || (cb->s_flags & (SF_ACKNOW|SF_WIN|SF_RXT)))
343 spx_output(cb, NULL);
344 cb->s_flags &= ~(SF_WIN|SF_RXT);
350 si->si_seq = ntohs(si->si_seq);
351 si->si_ack = ntohs(si->si_ack);
352 si->si_alo = ntohs(si->si_alo);
354 if (cb->s_ipxpcb->ipxp_socket->so_options & SO_DEBUG || traceallspxs)
355 spx_trace(SA_DROP, (u_char)ostate, cb, &spx_savesi, 0);
360 if (cb == 0 || cb->s_ipxpcb->ipxp_socket->so_options & SO_DEBUG ||
362 spx_trace(SA_DROP, (u_char)ostate, cb, &spx_savesi, 0);
366 static int spxrexmtthresh = 3;
369 * This is structurally similar to the tcp reassembly routine
370 * but its function is somewhat different: It merely queues
371 * packets up, and suppresses duplicates.
374 spx_reass(struct spxpcb *cb, struct spx *si, struct mbuf *si_m)
379 struct socket *so = cb->s_ipxpcb->ipxp_socket;
380 char packetp = cb->s_flags & SF_HI;
387 * Update our news from them.
389 if (si->si_cc & SPX_SA)
390 cb->s_flags |= (spx_use_delack ? SF_DELACK : SF_ACKNOW);
391 if (SSEQ_GT(si->si_alo, cb->s_ralo))
392 cb->s_flags |= SF_WIN;
393 if (SSEQ_LEQ(si->si_ack, cb->s_rack)) {
394 if ((si->si_cc & SPX_SP) && cb->s_rack != (cb->s_smax + 1)) {
395 spxstat.spxs_rcvdupack++;
397 * If this is a completely duplicate ack
398 * and other conditions hold, we assume
399 * a packet has been dropped and retransmit
400 * it exactly as in tcp_input().
402 if (si->si_ack != cb->s_rack ||
403 si->si_alo != cb->s_ralo)
405 else if (++cb->s_dupacks == spxrexmtthresh) {
406 u_short onxt = cb->s_snxt;
407 int cwnd = cb->s_cwnd;
409 cb->s_snxt = si->si_ack;
411 cb->s_force = 1 + SPXT_REXMT;
412 spx_output(cb, NULL);
413 cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
415 if (cwnd >= 4 * CUNIT)
416 cb->s_cwnd = cwnd / 2;
417 if (SSEQ_GT(onxt, cb->s_snxt))
427 * If our correspondent acknowledges data we haven't sent
428 * TCP would drop the packet after acking. We'll be a little
431 if (SSEQ_GT(si->si_ack, (cb->s_smax + 1))) {
432 spxstat.spxs_rcvacktoomuch++;
433 si->si_ack = cb->s_smax + 1;
435 spxstat.spxs_rcvackpack++;
437 * If transmit timer is running and timed sequence
438 * number was acked, update smoothed round trip time.
439 * See discussion of algorithm in tcp_input.c
441 if (cb->s_rtt && SSEQ_GT(si->si_ack, cb->s_rtseq)) {
442 spxstat.spxs_rttupdated++;
443 if (cb->s_srtt != 0) {
445 delta = cb->s_rtt - (cb->s_srtt >> 3);
446 if ((cb->s_srtt += delta) <= 0)
450 delta -= (cb->s_rttvar >> 2);
451 if ((cb->s_rttvar += delta) <= 0)
455 * No rtt measurement yet
457 cb->s_srtt = cb->s_rtt << 3;
458 cb->s_rttvar = cb->s_rtt << 1;
462 SPXT_RANGESET(cb->s_rxtcur,
463 ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1,
464 SPXTV_MIN, SPXTV_REXMTMAX);
467 * If all outstanding data is acked, stop retransmit
468 * timer and remember to restart (more output or persist).
469 * If there is more data to be acked, restart retransmit
470 * timer, using current (possibly backed-off) value;
472 if (si->si_ack == cb->s_smax + 1) {
473 cb->s_timer[SPXT_REXMT] = 0;
474 cb->s_flags |= SF_RXT;
475 } else if (cb->s_timer[SPXT_PERSIST] == 0)
476 cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
478 * When new data is acked, open the congestion window.
479 * If the window gives us less than ssthresh packets
480 * in flight, open exponentially (maxseg at a time).
481 * Otherwise open linearly (maxseg^2 / cwnd at a time).
484 if (cb->s_cwnd > cb->s_ssthresh)
485 incr = max(incr * incr / cb->s_cwnd, 1);
486 cb->s_cwnd = min(cb->s_cwnd + incr, cb->s_cwmx);
488 * Trim Acked data from output queue.
490 while ((m = so->so_snd.ssb_mb) != NULL) {
491 if (SSEQ_LT((mtod(m, struct spx *))->si_seq, si->si_ack))
492 sbdroprecord(&so->so_snd.sb);
497 cb->s_rack = si->si_ack;
499 if (SSEQ_LT(cb->s_snxt, cb->s_rack))
500 cb->s_snxt = cb->s_rack;
501 if (SSEQ_LT(cb->s_swl1, si->si_seq) || ((cb->s_swl1 == si->si_seq &&
502 (SSEQ_LT(cb->s_swl2, si->si_ack))) ||
503 (cb->s_swl2 == si->si_ack && SSEQ_LT(cb->s_ralo, si->si_alo)))) {
504 /* keep track of pure window updates */
505 if ((si->si_cc & SPX_SP) && cb->s_swl2 == si->si_ack
506 && SSEQ_LT(cb->s_ralo, si->si_alo)) {
507 spxstat.spxs_rcvwinupd++;
508 spxstat.spxs_rcvdupack--;
510 cb->s_ralo = si->si_alo;
511 cb->s_swl1 = si->si_seq;
512 cb->s_swl2 = si->si_ack;
513 cb->s_swnd = (1 + si->si_alo - si->si_ack);
514 if (cb->s_swnd > cb->s_smxw)
515 cb->s_smxw = cb->s_swnd;
516 cb->s_flags |= SF_WIN;
519 * If this packet number is higher than that which
520 * we have allocated refuse it, unless urgent
522 if (SSEQ_GT(si->si_seq, cb->s_alo)) {
523 if (si->si_cc & SPX_SP) {
524 spxstat.spxs_rcvwinprobe++;
527 spxstat.spxs_rcvpackafterwin++;
528 if (si->si_cc & SPX_OB) {
529 if (SSEQ_GT(si->si_seq, cb->s_alo + 60)) {
532 } /* else queue this packet; */
534 /*register struct socket *so = cb->s_ipxpcb->ipxp_socket;
535 if (so->so_state && SS_NOFDREF) {
545 * If this is a system packet, we don't need to
546 * queue it up, and won't update acknowledge #
548 if (si->si_cc & SPX_SP) {
552 * We have already seen this packet, so drop.
554 if (SSEQ_LT(si->si_seq, cb->s_ack)) {
556 spxstat.spxs_rcvduppack++;
557 if (si->si_seq == cb->s_ack - 1)
562 * Loop through all packets queued up to insert in
563 * appropriate sequence.
565 for (q = cb->s_q.si_next; q != &cb->s_q; q = q->si_next) {
566 if (si->si_seq == SI(q)->si_seq) {
567 spxstat.spxs_rcvduppack++;
570 if (SSEQ_LT(si->si_seq, SI(q)->si_seq)) {
571 spxstat.spxs_rcvoopack++;
575 nq = kmalloc(sizeof(struct spx_q), M_SPX_Q, M_INTNOWAIT);
580 insque(nq, q->si_prev);
583 * If this packet is urgent, inform process
585 if (si->si_cc & SPX_OB) {
586 cb->s_iobc = ((char *)si)[1 + sizeof(*si)];
588 cb->s_oobflags |= SF_IOOB;
591 #define SPINC sizeof(struct spxhdr)
593 * Loop through all packets queued up to update acknowledge
594 * number, and present all acknowledged data to user;
595 * If in packet interface mode, show packet headers.
597 for (q = cb->s_q.si_next; q != &cb->s_q; q = q->si_next) {
598 if (SI(q)->si_seq == cb->s_ack) {
601 if (SI(q)->si_cc & SPX_OB) {
602 cb->s_oobflags &= ~SF_IOOB;
603 if (so->so_rcv.ssb_cc)
604 so->so_oobmark = so->so_rcv.ssb_cc;
606 so->so_state |= SS_RCVATMARK;
613 spxstat.spxs_rcvpack++;
615 if (cb->s_flags2 & SF_NEWCALL) {
616 struct spxhdr *sp = mtod(m, struct spxhdr *);
617 u_char dt = sp->spx_dt;
619 if (dt != cb->s_rhdr.spx_dt) {
621 m_getclr(MB_DONTWAIT, MT_CONTROL);
626 cb->s_rhdr.spx_dt = dt;
627 mm->m_len = 5; /*XXX*/
630 *(u_char *)(&s[2]) = dt;
631 sbappend(&so->so_rcv.sb, mm);
634 if (sp->spx_cc & SPX_OB) {
635 m_chtype(m, MT_OOBDATA);
638 so->so_state &= ~SS_RCVATMARK;
643 m->m_pkthdr.len -= SPINC;
645 if ((sp->spx_cc & SPX_EM) || packetp) {
646 sbappendrecord(&so->so_rcv.sb, m);
649 sbappend(&so->so_rcv.sb, m);
653 sbappendrecord(&so->so_rcv.sb, m);
655 cb->s_rhdr = *mtod(m, struct spxhdr *);
658 m->m_pkthdr.len -= SPINC;
659 sbappend(&so->so_rcv.sb, m);
670 spx_ctlinput(int cmd, struct sockaddr *arg_as_sa, void *dummy)
672 caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
674 struct sockaddr_ipx *sipx;
676 if (cmd < 0 || cmd > PRC_NCMDS)
686 case PRC_HOSTUNREACH:
687 sipx = (struct sockaddr_ipx *)arg;
688 if (sipx->sipx_family != AF_IPX)
690 na = &sipx->sipx_addr;
700 spx_fixmtu(struct ipxpcb *ipxp)
702 struct spxpcb *cb = (struct spxpcb *)(ipxp->ipxp_pcb);
706 struct signalsockbuf *ssb;
708 struct mbuf *firstbad, *m0;
712 * The notification that we have sent
713 * too much is bad news -- we will
714 * have to go through queued up so far
715 * splitting ones which are too big and
716 * reassigning sequence numbers and checksums.
717 * we should then retransmit all packets from
718 * one above the offending packet to the last one
719 * we had sent (or our allocation)
720 * then the offending one so that the any queued
721 * data at our destination will be discarded.
723 ep = (struct ipx_errp *)ipxp->ipxp_notify_param;
724 ssb = &ipxp->ipxp_socket->so_snd;
725 cb->s_mtu = ep->ipx_err_param;
726 badseq = ep->ipx_err_ipx.si_seq;
727 for (m = ssb->ssb_mb; m != NULL; m = m->m_nextpkt) {
728 si = mtod(m, struct spx *);
729 if (si->si_seq == badseq)
736 /* calculate length */
737 for (m0 = m, len = 0; m != NULL; m = m->m_next)
739 if (len > cb->s_mtu) {
748 spx_output(struct spxpcb *cb, struct mbuf *m0)
750 struct socket *so = cb->s_ipxpcb->ipxp_socket;
751 struct mbuf *m = NULL;
752 struct spx *si = NULL;
753 struct signalsockbuf *ssb = &so->so_snd;
754 int len = 0, win, rcv_win;
755 short span, off, recordp = 0;
757 int error = 0, sendalot;
767 * Make sure that packet isn't too big.
769 for (m = m0; m != NULL; m = m->m_next) {
772 if (m->m_flags & M_EOR)
775 datalen = (cb->s_flags & SF_HO) ?
776 len - sizeof(struct spxhdr) : len;
778 if (cb->s_flags & SF_PI) {
782 int oldEM = cb->s_cc & SPX_EM;
787 * Here we are only being called
788 * from usrreq(), so it is OK to
791 m = m_copym(m0, 0, mtu, MB_WAIT);
792 if (cb->s_flags & SF_NEWCALL) {
796 mm->m_flags &= ~M_EOR;
800 error = spx_output(cb, m);
813 * Force length even, by adding a "garbage byte" if
818 if (M_TRAILINGSPACE(m) >= 1)
821 struct mbuf *m1 = m_get(MB_DONTWAIT, MT_DATA);
828 *(mtod(m1, u_char *)) = 0;
832 m = m_gethdr(MB_DONTWAIT, MT_HEADER);
838 * Fill in mbuf with extended SP header
839 * and addresses and length put into network format.
841 MH_ALIGN(m, sizeof(struct spx));
842 m->m_len = sizeof(struct spx);
844 si = mtod(m, struct spx *);
845 si->si_i = *cb->s_ipx;
846 si->si_s = cb->s_shdr;
847 if ((cb->s_flags & SF_PI) && (cb->s_flags & SF_HO)) {
849 if (m0->m_len < sizeof(*sh)) {
850 if((m0 = m_pullup(m0, sizeof(*sh))) == NULL) {
857 sh = mtod(m0, struct spxhdr *);
858 si->si_dt = sh->spx_dt;
859 si->si_cc |= sh->spx_cc & SPX_EM;
860 m0->m_len -= sizeof(*sh);
861 m0->m_data += sizeof(*sh);
865 if ((cb->s_flags2 & SF_NEWCALL) && recordp) {
869 if (cb->s_oobflags & SF_SOOB) {
872 * make sure OB packets convey exactly 1 byte.
873 * If the packet is 1 byte or larger, we
874 * have already guaranted there to be at least
875 * one garbage byte for the checksum, and
876 * extra bytes shouldn't hurt!
878 if (len > sizeof(*si)) {
880 len = (1 + sizeof(*si));
883 si->si_len = htons((u_short)len);
884 m->m_pkthdr.len = ((len - 1) | 1) + 1;
886 * queue stuff up for output
888 sbappendrecord(&ssb->sb, m);
892 idle = (cb->s_smax == (cb->s_rack - 1));
896 off = cb->s_snxt - cb->s_rack;
897 win = min(cb->s_swnd, (cb->s_cwnd / CUNIT));
900 * If in persist timeout with window of 0, send a probe.
901 * Otherwise, if window is small but nonzero
902 * and timer expired, send what we can and go into
905 if (cb->s_force == 1 + SPXT_PERSIST) {
907 cb->s_timer[SPXT_PERSIST] = 0;
911 span = cb->s_seq - cb->s_rack;
912 len = min(span, win) - off;
916 * Window shrank after we went into it.
917 * If window shrank to 0, cancel pending
918 * restransmission and pull s_snxt back
919 * to (closed) window. We will enter persist
920 * state below. If the widndow didn't close completely,
921 * just wait for an ACK.
925 cb->s_timer[SPXT_REXMT] = 0;
926 cb->s_snxt = cb->s_rack;
931 rcv_win = ssb_space(&so->so_rcv);
934 * Send if we owe peer an ACK.
936 if (cb->s_oobflags & SF_SOOB) {
938 * must transmit this out of band packet
940 cb->s_oobflags &= ~ SF_SOOB;
942 spxstat.spxs_sndurg++;
945 if (cb->s_flags & SF_ACKNOW)
947 if (cb->s_state < TCPS_ESTABLISHED)
950 * Silly window can't happen in spx.
951 * Code from tcp deleted.
956 * Compare available window to amount of window
957 * known to peer (as advertised window less
958 * next expected input.) If the difference is at least two
959 * packets or at least 35% of the mximum possible window,
960 * then want to send a window update to peer.
963 u_short delta = 1 + cb->s_alo - cb->s_ack;
964 int adv = rcv_win - (delta * cb->s_mtu);
966 if ((so->so_rcv.ssb_cc == 0 && adv >= (2 * cb->s_mtu)) ||
967 (100 * adv / so->so_rcv.ssb_hiwat >= 35)) {
968 spxstat.spxs_sndwinup++;
969 cb->s_flags |= SF_ACKNOW;
975 * Many comments from tcp_output.c are appropriate here
977 * If send window is too small, there is data to transmit, and no
978 * retransmit or persist is pending, then go to persist state.
979 * If nothing happens soon, send when timer expires:
980 * if window is nonzero, transmit what we can,
981 * otherwise send a probe.
983 if (so->so_snd.ssb_cc && cb->s_timer[SPXT_REXMT] == 0 &&
984 cb->s_timer[SPXT_PERSIST] == 0) {
989 * No reason to send a packet, just return.
996 * Find requested packet.
1000 cb->s_want = cb->s_snxt;
1001 for (m = ssb->ssb_mb; m != NULL; m = m->m_nextpkt) {
1002 si = mtod(m, struct spx *);
1003 if (SSEQ_LEQ(cb->s_snxt, si->si_seq))
1008 if (si->si_seq == cb->s_snxt)
1011 spxstat.spxs_sndvoid++, si = 0;
1019 alo = cb->s_ack - 1 + (rcv_win / ((short)cb->s_mtu));
1020 if (SSEQ_LT(alo, cb->s_alo))
1025 * must make a copy of this packet for
1026 * ipx_output to monkey with
1028 m = m_copy(m, 0, (int)M_COPYALL);
1032 si = mtod(m, struct spx *);
1033 if (SSEQ_LT(si->si_seq, cb->s_smax))
1034 spxstat.spxs_sndrexmitpack++;
1036 spxstat.spxs_sndpack++;
1037 } else if (cb->s_force || cb->s_flags & SF_ACKNOW) {
1039 * Must send an acknowledgement or a probe
1042 spxstat.spxs_sndprobe++;
1043 if (cb->s_flags & SF_ACKNOW)
1044 spxstat.spxs_sndacks++;
1045 m = m_gethdr(MB_DONTWAIT, MT_HEADER);
1049 * Fill in mbuf with extended SP header
1050 * and addresses and length put into network format.
1052 MH_ALIGN(m, sizeof(struct spx));
1053 m->m_len = sizeof(*si);
1054 m->m_pkthdr.len = sizeof(*si);
1055 si = mtod(m, struct spx *);
1056 si->si_i = *cb->s_ipx;
1057 si->si_s = cb->s_shdr;
1058 si->si_seq = cb->s_smax + 1;
1059 si->si_len = htons(sizeof(*si));
1060 si->si_cc |= SPX_SP;
1063 if (so->so_options & SO_DEBUG || traceallspxs)
1064 spx_trace(SA_OUTPUT, cb->s_state, cb, si, 0);
1068 * Stuff checksum and output datagram.
1070 if ((si->si_cc & SPX_SP) == 0) {
1071 if (cb->s_force != (1 + SPXT_PERSIST) ||
1072 cb->s_timer[SPXT_PERSIST] == 0) {
1074 * If this is a new packet and we are not currently
1075 * timing anything, time this one.
1077 if (SSEQ_LT(cb->s_smax, si->si_seq)) {
1078 cb->s_smax = si->si_seq;
1079 if (cb->s_rtt == 0) {
1080 spxstat.spxs_segstimed++;
1081 cb->s_rtseq = si->si_seq;
1086 * Set rexmt timer if not currently set,
1087 * Initial value for retransmit timer is smoothed
1088 * round-trip time + 2 * round-trip time variance.
1089 * Initialize shift counter which is used for backoff
1090 * of retransmit time.
1092 if (cb->s_timer[SPXT_REXMT] == 0 &&
1093 cb->s_snxt != cb->s_rack) {
1094 cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
1095 if (cb->s_timer[SPXT_PERSIST]) {
1096 cb->s_timer[SPXT_PERSIST] = 0;
1100 } else if (SSEQ_LT(cb->s_smax, si->si_seq)) {
1101 cb->s_smax = si->si_seq;
1103 } else if (cb->s_state < TCPS_ESTABLISHED) {
1105 cb->s_rtt = 1; /* Time initial handshake */
1106 if (cb->s_timer[SPXT_REXMT] == 0)
1107 cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
1111 * Do not request acks when we ack their data packets or
1112 * when we do a gratuitous window update.
1114 if (((si->si_cc & SPX_SP) == 0) || cb->s_force)
1115 si->si_cc |= SPX_SA;
1116 si->si_seq = htons(si->si_seq);
1117 si->si_alo = htons(alo);
1118 si->si_ack = htons(cb->s_ack);
1121 si->si_sum = ipx_cksum(m, ntohs(si->si_len));
1123 si->si_sum = 0xffff;
1126 if (so->so_options & SO_DEBUG || traceallspxs)
1127 spx_trace(SA_OUTPUT, cb->s_state, cb, si, 0);
1129 if (so->so_options & SO_DONTROUTE)
1130 error = ipx_outputfl(m, NULL, IPX_ROUTETOIF);
1132 error = ipx_outputfl(m, &cb->s_ipxpcb->ipxp_route, 0);
1137 spxstat.spxs_sndtotal++;
1139 * Data sent (as far as we can tell).
1140 * If this advertises a larger window than any other segment,
1141 * then remember the size of the advertized window.
1142 * Any pending ACK has now been sent.
1145 cb->s_flags &= ~(SF_ACKNOW|SF_DELACK);
1146 if (SSEQ_GT(alo, cb->s_alo))
1154 static int spx_do_persist_panics = 0;
1157 spx_setpersist(struct spxpcb *cb)
1159 int t = ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1;
1161 if (cb->s_timer[SPXT_REXMT] && spx_do_persist_panics)
1162 panic("spx_output REXMT");
1164 * Start/restart persistance timer.
1166 SPXT_RANGESET(cb->s_timer[SPXT_PERSIST],
1167 t*spx_backoff[cb->s_rxtshift],
1168 SPXTV_PERSMIN, SPXTV_PERSMAX);
1169 if (cb->s_rxtshift < SPX_MAXRXTSHIFT)
1174 spx_ctloutput(struct socket *so, struct sockopt *sopt)
1176 struct ipxpcb *ipxp = sotoipxpcb(so);
1185 if (sopt->sopt_level != IPXPROTO_SPX) {
1186 /* This will have to be changed when we do more general
1187 stacking of protocols */
1188 return (ipx_ctloutput(so, sopt));
1193 cb = ipxtospxpcb(ipxp);
1195 switch (sopt->sopt_dir) {
1197 switch (sopt->sopt_name) {
1198 case SO_HEADERS_ON_INPUT:
1202 case SO_HEADERS_ON_OUTPUT:
1205 soptval = cb->s_flags & mask;
1206 error = sooptcopyout(sopt, &soptval, sizeof soptval);
1210 usoptval = cb->s_mtu;
1211 error = sooptcopyout(sopt, &usoptval, sizeof usoptval);
1214 case SO_LAST_HEADER:
1215 error = sooptcopyout(sopt, &cb->s_rhdr,
1219 case SO_DEFAULT_HEADERS:
1220 error = sooptcopyout(sopt, &cb->s_shdr,
1225 error = ENOPROTOOPT;
1230 switch (sopt->sopt_name) {
1231 /* XXX why are these shorts on get and ints on set?
1232 that doesn't make any sense... */
1233 case SO_HEADERS_ON_INPUT:
1237 case SO_HEADERS_ON_OUTPUT:
1240 error = sooptcopyin(sopt, &optval, sizeof optval,
1245 if (cb->s_flags & SF_PI) {
1247 cb->s_flags |= mask;
1249 cb->s_flags &= ~mask;
1250 } else error = EINVAL;
1254 error = sooptcopyin(sopt, &usoptval, sizeof usoptval,
1258 cb->s_mtu = usoptval;
1263 error = sooptcopyin(sopt, &optval, sizeof optval,
1268 cb->s_flags2 |= SF_NEWCALL;
1271 cb->s_flags2 &= ~SF_NEWCALL;
1277 case SO_DEFAULT_HEADERS:
1281 error = sooptcopyin(sopt, &sp, sizeof sp,
1285 cb->s_dt = sp.spx_dt;
1286 cb->s_cc = sp.spx_cc & SPX_EM;
1291 error = ENOPROTOOPT;
1299 spx_usr_abort(struct socket *so)
1301 struct ipxpcb *ipxp;
1304 ipxp = sotoipxpcb(so);
1305 cb = ipxtospxpcb(ipxp);
1308 spx_drop(cb, ECONNABORTED);
1314 * Accept a connection. Essentially all the work is
1315 * done at higher levels; just return the address
1316 * of the peer, storing through addr.
1319 spx_accept(struct socket *so, struct sockaddr **nam)
1321 struct ipxpcb *ipxp;
1322 struct sockaddr_ipx *sipx, ssipx;
1324 ipxp = sotoipxpcb(so);
1326 bzero(sipx, sizeof *sipx);
1327 sipx->sipx_len = sizeof *sipx;
1328 sipx->sipx_family = AF_IPX;
1329 sipx->sipx_addr = ipxp->ipxp_faddr;
1330 *nam = dup_sockaddr((struct sockaddr *)sipx);
1335 spx_attach(struct socket *so, int proto, struct pru_attach_info *ai)
1338 struct ipxpcb *ipxp;
1341 struct signalsockbuf *ssb;
1343 ipxp = sotoipxpcb(so);
1344 cb = ipxtospxpcb(ipxp);
1349 error = ipx_pcballoc(so, &ipxpcb);
1351 goto spx_attach_end;
1352 if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) {
1353 error = soreserve(so, (u_long) 3072, (u_long) 3072,
1356 goto spx_attach_end;
1358 ipxp = sotoipxpcb(so);
1360 MALLOC(cb, struct spxpcb *, sizeof *cb, M_PCB, M_INTWAIT | M_ZERO);
1363 mm = m_getclr(MB_DONTWAIT, MT_HEADER);
1367 goto spx_attach_end;
1370 cb->s_ipx = mtod(mm, struct ipx *);
1371 cb->s_state = TCPS_LISTEN;
1374 cb->s_q.si_next = cb->s_q.si_prev = &cb->s_q;
1375 cb->s_ipxpcb = ipxp;
1376 cb->s_mtu = 576 - sizeof(struct spx);
1377 cb->s_cwnd = ssb_space(ssb) * CUNIT / cb->s_mtu;
1378 cb->s_ssthresh = cb->s_cwnd;
1379 cb->s_cwmx = ssb_space(ssb) * CUNIT / (2 * sizeof(struct spx));
1380 /* Above is recomputed when connecting to account
1381 for changed buffering or mtu's */
1382 cb->s_rtt = SPXTV_SRTTBASE;
1383 cb->s_rttvar = SPXTV_SRTTDFLT << 2;
1384 SPXT_RANGESET(cb->s_rxtcur,
1385 ((SPXTV_SRTTBASE >> 2) + (SPXTV_SRTTDFLT << 2)) >> 1,
1386 SPXTV_MIN, SPXTV_REXMTMAX);
1387 ipxp->ipxp_pcb = (caddr_t)cb;
1394 spx_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
1396 struct ipxpcb *ipxp;
1398 ipxp = sotoipxpcb(so);
1400 return (ipx_pcbbind(ipxp, nam, td));
1404 * Initiate connection to peer.
1405 * Enter SYN_SENT state, and mark socket as connecting.
1406 * Start keep-alive timer, setup prototype header,
1407 * Send initial system packet requesting connection.
1410 spx_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1413 struct ipxpcb *ipxp;
1416 ipxp = sotoipxpcb(so);
1417 cb = ipxtospxpcb(ipxp);
1420 if (ipxp->ipxp_lport == 0) {
1421 error = ipx_pcbbind(ipxp, NULL, td);
1423 goto spx_connect_end;
1425 error = ipx_pcbconnect(ipxp, nam, td);
1427 goto spx_connect_end;
1429 spxstat.spxs_connattempt++;
1430 cb->s_state = TCPS_SYN_SENT;
1433 cb->s_timer[SPXT_KEEP] = SPXTV_KEEP;
1434 cb->s_force = 1 + SPXTV_KEEP;
1436 * Other party is required to respond to
1437 * the port I send from, but he is not
1438 * required to answer from where I am sending to,
1439 * so allow wildcarding.
1440 * original port I am sending to is still saved in
1443 ipxp->ipxp_fport = 0;
1444 error = spx_output(cb, NULL);
1451 spx_detach(struct socket *so)
1453 struct ipxpcb *ipxp;
1456 ipxp = sotoipxpcb(so);
1457 cb = ipxtospxpcb(ipxp);
1462 if (cb->s_state > TCPS_LISTEN)
1471 * We may decide later to implement connection closing
1472 * handshaking at the spx level optionally.
1473 * here is the hook to do it:
1476 spx_usr_disconnect(struct socket *so)
1478 struct ipxpcb *ipxp;
1481 ipxp = sotoipxpcb(so);
1482 cb = ipxtospxpcb(ipxp);
1491 spx_listen(struct socket *so, struct thread *td)
1494 struct ipxpcb *ipxp;
1498 ipxp = sotoipxpcb(so);
1499 cb = ipxtospxpcb(ipxp);
1501 if (ipxp->ipxp_lport == 0)
1502 error = ipx_pcbbind(ipxp, NULL, td);
1504 cb->s_state = TCPS_LISTEN;
1509 * After a receive, possibly send acknowledgment
1510 * updating allocation.
1513 spx_rcvd(struct socket *so, int flags)
1515 struct ipxpcb *ipxp;
1518 ipxp = sotoipxpcb(so);
1519 cb = ipxtospxpcb(ipxp);
1522 cb->s_flags |= SF_RVD;
1523 spx_output(cb, NULL);
1524 cb->s_flags &= ~SF_RVD;
1530 spx_rcvoob(struct socket *so, struct mbuf *m, int flags)
1532 struct ipxpcb *ipxp;
1535 ipxp = sotoipxpcb(so);
1536 cb = ipxtospxpcb(ipxp);
1538 if ((cb->s_oobflags & SF_IOOB) || so->so_oobmark ||
1539 (so->so_state & SS_RCVATMARK)) {
1541 *mtod(m, caddr_t) = cb->s_iobc;
1548 spx_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
1549 struct mbuf *controlp, struct thread *td)
1552 struct ipxpcb *ipxp;
1556 ipxp = sotoipxpcb(so);
1557 cb = ipxtospxpcb(ipxp);
1560 if (flags & PRUS_OOB) {
1561 if (ssb_space(&so->so_snd) < -512) {
1565 cb->s_oobflags |= SF_SOOB;
1567 if (controlp != NULL) {
1568 u_short *p = mtod(controlp, u_short *);
1570 if ((p[0] == 5) && (p[1] == 1)) { /* XXXX, for testing */
1571 cb->s_shdr.spx_dt = *(u_char *)(&p[2]);
1577 error = spx_output(cb, m);
1580 if (controlp != NULL)
1589 spx_shutdown(struct socket *so)
1592 struct ipxpcb *ipxp;
1596 ipxp = sotoipxpcb(so);
1597 cb = ipxtospxpcb(ipxp);
1601 cb = spx_usrclosed(cb);
1603 error = spx_output(cb, NULL);
1609 spx_sp_attach(struct socket *so, int proto, struct pru_attach_info *ai)
1612 struct ipxpcb *ipxp;
1614 error = spx_attach(so, proto, ai);
1616 ipxp = sotoipxpcb(so);
1617 ((struct spxpcb *)ipxp->ipxp_pcb)->s_flags |=
1618 (SF_HI | SF_HO | SF_PI);
1624 * Create template to be used to send spx packets on a connection.
1625 * Called after host entry created, fills
1626 * in a skeletal spx header (choosing connection id),
1627 * minimizing the amount of work necessary when the connection is used.
1630 spx_template(struct spxpcb *cb)
1632 struct ipxpcb *ipxp = cb->s_ipxpcb;
1633 struct ipx *ipx = cb->s_ipx;
1634 struct signalsockbuf *ssb = &(ipxp->ipxp_socket->so_snd);
1636 ipx->ipx_pt = IPXPROTO_SPX;
1637 ipx->ipx_sna = ipxp->ipxp_laddr;
1638 ipx->ipx_dna = ipxp->ipxp_faddr;
1639 cb->s_sid = htons(spx_iss);
1640 spx_iss += SPX_ISSINCR/2;
1642 cb->s_cwnd = (ssb_space(ssb) * CUNIT) / cb->s_mtu;
1643 cb->s_ssthresh = cb->s_cwnd; /* Try to expand fast to full complement
1645 cb->s_cwmx = (ssb_space(ssb) * CUNIT) / (2 * sizeof(struct spx));
1646 cb->s_cwmx = max(cb->s_cwmx, cb->s_cwnd);
1647 /* But allow for lots of little packets as well */
1651 * Close a SPIP control block:
1652 * discard spx control block itself
1653 * discard ipx protocol control block
1654 * wake up any sleepers
1656 static struct spxpcb *
1657 spx_close(struct spxpcb *cb)
1661 struct ipxpcb *ipxp = cb->s_ipxpcb;
1662 struct socket *so = ipxp->ipxp_socket;
1665 q = cb->s_q.si_next;
1666 while (q != &(cb->s_q)) {
1674 m_free(cb->s_ipx_m);
1677 soisdisconnected(so);
1678 ipx_pcbdetach(ipxp);
1679 spxstat.spxs_closed++;
1684 * Someday we may do level 3 handshaking
1685 * to close a connection or send a xerox style error.
1686 * For now, just close.
1688 static struct spxpcb *
1689 spx_usrclosed(struct spxpcb *cb)
1691 return (spx_close(cb));
1694 static struct spxpcb *
1695 spx_disconnect(struct spxpcb *cb)
1697 return (spx_close(cb));
1701 * Drop connection, reporting
1702 * the specified error.
1704 static struct spxpcb *
1705 spx_drop(struct spxpcb *cb, int errno)
1707 struct socket *so = cb->s_ipxpcb->ipxp_socket;
1710 * someday, in the xerox world
1711 * we will generate error protocol packets
1712 * announcing that the socket has gone away.
1714 if (TCPS_HAVERCVDSYN(cb->s_state)) {
1715 spxstat.spxs_drops++;
1716 cb->s_state = TCPS_CLOSED;
1719 spxstat.spxs_conndrops++;
1720 so->so_error = errno;
1721 return (spx_close(cb));
1725 * Fast timeout routine for processing delayed acks
1730 struct ipxpcb *ipxp;
1734 ipxp = ipxpcb.ipxp_next;
1736 for (; ipxp != &ipxpcb; ipxp = ipxp->ipxp_next) {
1737 if ((cb = (struct spxpcb *)ipxp->ipxp_pcb) != NULL &&
1738 (cb->s_flags & SF_DELACK)) {
1739 cb->s_flags &= ~SF_DELACK;
1740 cb->s_flags |= SF_ACKNOW;
1741 spxstat.spxs_delack++;
1742 spx_output(cb, NULL);
1750 * spx protocol timeout routine called every 500 ms.
1751 * Updates the timers in all active pcb's and
1752 * causes finite state machine actions if timers expire.
1757 struct ipxpcb *ip, *ipnxt;
1762 * Search through tcb's and update active timers.
1765 ip = ipxpcb.ipxp_next;
1770 while (ip != &ipxpcb) {
1771 cb = ipxtospxpcb(ip);
1772 ipnxt = ip->ipxp_next;
1775 for (i = 0; i < SPXT_NTIMERS; i++) {
1776 if (cb->s_timer[i] && --cb->s_timer[i] == 0) {
1778 if (ipnxt->ipxp_prev != ip)
1788 spx_iss += SPX_ISSINCR/PR_SLOWHZ; /* increment iss */
1793 * SPX timer processing.
1795 static struct spxpcb *
1796 spx_timers(struct spxpcb *cb, int timer)
1801 cb->s_force = 1 + timer;
1805 * 2 MSL timeout in shutdown went off. TCP deletes connection
1809 kprintf("spx: SPXT_2MSL went off for no reason\n");
1810 cb->s_timer[timer] = 0;
1814 * Retransmission timer went off. Message has not
1815 * been acked within retransmit interval. Back off
1816 * to a longer retransmit interval and retransmit one packet.
1819 if (++cb->s_rxtshift > SPX_MAXRXTSHIFT) {
1820 cb->s_rxtshift = SPX_MAXRXTSHIFT;
1821 spxstat.spxs_timeoutdrop++;
1822 cb = spx_drop(cb, ETIMEDOUT);
1825 spxstat.spxs_rexmttimeo++;
1826 rexmt = ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1;
1827 rexmt *= spx_backoff[cb->s_rxtshift];
1828 SPXT_RANGESET(cb->s_rxtcur, rexmt, SPXTV_MIN, SPXTV_REXMTMAX);
1829 cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
1831 * If we have backed off fairly far, our srtt
1832 * estimate is probably bogus. Clobber it
1833 * so we'll take the next rtt measurement as our srtt;
1834 * move the current srtt into rttvar to keep the current
1835 * retransmit times until then.
1837 if (cb->s_rxtshift > SPX_MAXRXTSHIFT / 4 ) {
1838 cb->s_rttvar += (cb->s_srtt >> 2);
1841 cb->s_snxt = cb->s_rack;
1843 * If timing a packet, stop the timer.
1847 * See very long discussion in tcp_timer.c about congestion
1848 * window and sstrhesh
1850 win = min(cb->s_swnd, (cb->s_cwnd/CUNIT)) / 2;
1854 cb->s_ssthresh = win * CUNIT;
1855 spx_output(cb, NULL);
1859 * Persistance timer into zero window.
1860 * Force a probe to be sent.
1863 spxstat.spxs_persisttimeo++;
1865 spx_output(cb, NULL);
1869 * Keep-alive timer went off; send something
1870 * or drop connection if idle for too long.
1873 spxstat.spxs_keeptimeo++;
1874 if (cb->s_state < TCPS_ESTABLISHED)
1876 if (cb->s_ipxpcb->ipxp_socket->so_options & SO_KEEPALIVE) {
1877 if (cb->s_idle >= SPXTV_MAXIDLE)
1879 spxstat.spxs_keepprobe++;
1880 spx_output(cb, NULL);
1883 cb->s_timer[SPXT_KEEP] = SPXTV_KEEP;
1886 spxstat.spxs_keepdrops++;
1887 cb = spx_drop(cb, ETIMEDOUT);